Based on this product's specifications, here are some alternatives and similar models
Unidelta straight equal-through PE pipe connector 40 x 40 mm (model 601040)
Summary description:
Straight equal-through PE pipe connector by Unidelta, size 40 x 40 mm, model 601040. Designed to join two polyethylene (PE) pipes of the same 40 mm diameter in a straight line. Suitable for potable water, irrigation, drainage and general low-pressure fluid distribution systems where a reliable inline mechanical joint is required.